This CB9 monoclonal antibody reacts with human Granzyme A. Granzyme A is the most abundantly expressed of the granzyme serine proteases, which are proteins released from the granules of NK cells and cytotoxic T lymphocytes that induce death in target cells by cleavage of intracellular substrates. They play a critical role in immune defense against viruses, tumors, and intracellular bacteria. Granzyme A activates caspase-independent cell death pathways morphologically similar to apoptosis and characterized by mitochondrial and DNA damage. It may also play a role in inflammation, as the precursor form of IL-1 beta (pro-IL-1 beta) is among its target substrates. Granzyme A shares overlapping substrate specificity with the closely-related Granzyme K, which is believed to account for the minimal decrease in cytotoxicity of Granzyme A-deficient CTL.